<html>

<a href="https://www.youtube.com">go to youtube</a>
<br>


<iframe id="1" src="http://www.eurosport.fr"></iframe>


<button onclick="document.getElementById('1').src='https://fr.wikipedia.org';">iframe 2</button>


<button onclick="attack()">Start Attack</button>


<script>


function attack(){

for(var i=0;i<2;i++){

window.history.forward();

}


}


</script>


</html>